Smith finished second in the NFL behind Houston's J.J. Watt with 19.5 sacks during the regular season, but hasn't logged one since Week 14. Part of his failure to get to the quarterback could be attributed to injured defensive end Justin Smith's absence late in the year.

Justin Smith returned for the postseason, and if his injured elbow/triceps continues to strengthen with two weeks between games it could help the defense's ability to pressure Baltimore Ravens quarterback Joe Flacco on Sunday.

"Justin not being in there plays a part in (sacks)," Harbaugh said Monday. "We love having Justin in there. The play of Aldon has been really good. He played the run really well (against Atlanta). Sacks are the low-hanging fruit that you see. They don't always see the other things Aldon is doing game in and game out."

Harbaugh offered high praise for Justin Smith, the 33-year-old veteran who returned for the playoffs after missing the final two regular-season games.

"Justin Smith is one of the greatest players ever to play in the National Football League," Harbaugh said. "Everybody should have a Justin Smith on their team."

The Smiths will have their work cut out Sunday to put pressure on Flacco, who was sacked 35 times during the regular season.

Harbaugh considers Flacco one of the best quarterbacks in the NFL.

"Outstanding quarterback, winning quarterback, just a tremendous habit of success," Harbaugh said. "Tremendous throwing action and arm talent. A winning quarterback, He's a football player. I don't know if you can give a guy a higher compliment than that."

GOOD - ALBEIT UNHAPPY - SOLDIER: Reports indicate Alex Smith, deposed by Colin Kaepernick as the 49ers' starting quarterback in November, has requested his release after the Super Bowl. Harbaugh painted a picture Monday of Smith as the good soldier since the switch.

"He's prepared and been involved in the game-planning. He's prepared himself as the starter each week. That's what expected of him," Harbaugh said.

"(He's) another person to credit in Colin's success. Alex has really helped coached Colin. He coaches Colin now more than I do. That speaks volumes for the kind of teammate and person that Alex is."

BO KNEW: The late Bo Schembechler, who was Harbaugh's coach at Michigan, left a lasting impression.

"Next to my dad, right on the same level as my Dad (Jack), is Bo Schembechler," Harbaugh said. "To me, he's one of the greatest coaches to coach the game. I've studied (former Ohio State coach) Woody Hayes quite extensively. To my mind, those are the three coaches I try most to emulate."

SAFE ANSWER: Harbaugh sidestepped a question about President Obama's concern about the future safety of football. Obama said over the weekend that if he had a son he'd be reluctant to have him play football.

"I have a 4-month-old soon to be 5-month-old son, Jack Harbaugh. If President Obama feels that way, that's a little less competition for him," Harbaugh said.

SPLIT LOYALTIES: Jack and Jackie Harbaugh have the most talked-about players in America this week. Their allegiances will be split between the coach of the 49ers and their older son, Ravens coach John Harbaugh.

"I know they're excited," Jim Harbaugh said. "I've talked to them a few times. They're very much looking forward to the game."

NO CURFEW: Despite the temptations that the French Quarter offers, Harbaugh said he won't impose a curfew on his players.

The 49ers appear to be treating the Super Bowl as a business trip. Players refrained from taking pictures and videos of their arrival Sunday in New Orleans.